Hi there and welcome to the forum,
Thanks for the great comments

Yes, I have thought about how to do this. The problem is that I don't want the script to get to complicated and require "external" form elements for updateing each day.
One possible solution that I had though of was to have several states:
Available all day
Booked all day
Booked morning
Booked afternoon
In the code, it would initually be set to available, then you would have to click it several times to get to the state that you required ie:
1 click : booked all day (do this first as it the most likely state)
2 click: booked morning
3 click: booked afternoon
A fourth click would then get it back to available.
Clearly 2 new sets of numbers would be required to indicate the alternative states.
However I am not sure if this might be a bit tedious - having to click (and wait) 3 times to say that it is booked in the afternoon...
As someone who would like to see such a function - what do you think of this solution?
Looking forward to your input.
Chris